Quantum dot photoelectric detector array with crosstalk suppression function and preparation method thereof

Abstract

The invention discloses a quantum dot photoelectric detector array with a crosstalk suppression function and a preparation method of the quantum dot photoelectric detector array. The quantum dot photoelectric detector array comprises an insulating substrate, a bottom electrode layer, a nickel oxide thin film, a quantum dot thin film, a functional layer and a top electrode layer which are arranged in a stacked mode. The bottom electrode layer comprises a plurality of metal blocks arranged in an array; a gap is formed between every two adjacent metal blocks, and the insulating substrate is embedded into the gaps between the metal blocks; each metal block corresponds to one pixel position; the multiple quantum dot film units are arranged in an array, gaps are formed between the adjacent quantum dot film units, the semiconductor material corresponding to the functional layer is embedded into the gaps between the quantum dot film units to form an isolation layer film, and each quantum dot film unit corresponds to one pixel position. The semiconductor material is embedded into the gap between the adjacent quantum dot film units, so that the movement of a photon-generated carrier between adjacent pixels when the device works is effectively inhibited, and the detection effect of the device is improved by efficiently inhibiting crosstalk.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a quantum dot photodetector array with crosstalk suppression function and its fabrication method. Background Technology

[0002] A photodetector is a semiconductor device that converts the energy of incident photons into a measurable electrical signal using the photoelectric effect. Among them, short-wave infrared photodetectors, with their specific response capability in the critical atmospheric window band of 1.4-2.5 μm, play an irreplaceable role in fields such as biomedical engineering, military operations, and communications. Currently, the common absorber layer material for short-wave infrared photodetectors is indium gallium arsenide (InGaAs). InGaAs photodetectors have advantages such as high quantum efficiency and mature manufacturing processes; however, due to the lattice mismatch between InGaAs and silicon, large-scale InGaAs arrays require indium pillar flip-flops to interconnect with CMOS (Complementary Metal-Oxide-Semiconductor) readout circuits. The complex fabrication process and high cost limit its development in the low-cost field. Lead sulfide colloidal quantum dots (PbS Colloidal Quantum Dots, PbS CQDs) have advantages such as low cost, tunable bandgap, suitability for large-area fabrication, and monolithic integration with silicon CQD large-scale integrated circuits; they show great promise for applications in infrared photodetectors. Unlike traditional indium gallium arsenide (IGaAs) photodetectors, the absorption and isolation layers in lead sulfide colloidal quantum dot photodetectors can be fabricated using a solution spin-coating method, resulting in a simple and low-cost process. Furthermore, lead sulfide colloidal quantum dot photodetectors can be monolithically integrated with silicon-based readout circuits without flip-chip bonding, enabling higher pixel densities than traditional infrared image sensors. As applications demand increasingly higher resolution (higher resolution requires higher pixel density), pixel size and spacing are shrinking, leading to issues such as pixel uniformity and crosstalk suppression. Crosstalk between adjacent pixels intensifies with decreasing pixel spacing, blurring image edges and reducing resolution. Therefore, existing lead sulfide colloidal quantum dot photodetectors suffer from poor detection performance due to crosstalk at higher pixel densities. Summary of the Invention

[0003] This invention provides a quantum dot photodetector array with crosstalk suppression function and its fabrication method, aiming to solve the problem of poor detection performance caused by crosstalk in existing lead sulfide colloidal quantum dot photodetectors at high pixel densities.

[0004] In a first aspect, embodiments of this application provide a quantum dot photodetector array with crosstalk suppression function, wherein the quantum dot photodetector array includes an insulating substrate, a bottom electrode layer, a nickel oxide thin film, a quantum dot thin film, a functional layer and a top electrode layer stacked together. The bottom electrode layer includes multiple metal blocks arranged in an array; there are gaps between adjacent metal blocks, and the insulating substrate is embedded in the gaps between the metal blocks; each metal block corresponds to a pixel position; the functional layer is made of semiconductor material. The quantum dot film includes multiple quantum dot film units arranged in an array, with gaps between adjacent quantum dot film units. Semiconductor material embedded in the gaps between the quantum dot film units forms an isolation layer, and each quantum dot film unit corresponds to a pixel position.

[0005] Secondly, embodiments of this application also provide a preparation method, wherein the preparation method is used to prepare a quantum dot photodetector array with crosstalk suppression function as described in the first aspect above, the preparation method comprising: The bottom electrode pattern is prepared by photolithography, and then transferred to the silicon dioxide layer of the insulating substrate by etching. The insulating substrate is placed in a magnetron sputtering instrument and sputtered at a sputtering power of 50~100W for 1.5~4 minutes to obtain a patterned bottom electrode layer. The insulating substrate is then thermally oxidized to form a silicon dioxide layer. An insulating substrate with a bottom electrode layer is placed in a nitrogen glove box and a nickel oxide film is spin-coated. The spin-coating speed of the nickel oxide film is 3000~6000 rpm and the spin-coating time is 25~60 seconds. Two layers are spin-coated. After the first layer is spin-coated, the substrate is annealed in air at 80~120℃ for 8~15 minutes. After the first layer is spin-coated, the substrate is annealed in air at 280~340℃ for 0.8~1.5 hours. An insulating substrate with a spin-coated nickel oxide film is placed in a nitrogen glove box for spin-coating a quantum dot film. The spin-coating speed of the quantum dot film is 1600~3000 rpm and the spin-coating time is 15~30 seconds. The silicon wafer after spin-coating to form a quantum dot film is placed in a solution containing a zinc iodide-mercaptopropionic acid mixed ligand for ligand exchange. The spin-coating and ligand exchange of the quantum dot film are repeated 3 times. The quantum dot film was patterned using a high-hardness custom mold via nanoimprinting and then annealed at 60-100°C for 8-15 minutes. Semiconductor materials are spin-coated in an air environment to form an electron transport layer and an isolation layer, wherein the spin-coating speed of the semiconductor material is 1600~3000 rpm and the spin-coating time is 15~30 seconds; The top electrode layer is sputtered by magnetron sputtering, with a sputtering power of 35-70W and a sputtering time of 24-40 minutes.

[0006] This invention provides a quantum dot photodetector array with crosstalk suppression function and its fabrication method. The quantum dot photodetector array includes a stacked insulating substrate, a bottom electrode layer, a nickel oxide thin film, a quantum dot thin film, a functional layer, and a top electrode layer. The bottom electrode layer includes multiple metal blocks arranged in an array. Gaps exist between adjacent metal blocks, and the insulating substrate is embedded within these gaps. Each metal block corresponds to a pixel position. Multiple quantum dot thin film units are arranged in an array, with gaps between adjacent units. The semiconductor material corresponding to the functional layer is embedded within the gaps between the quantum dot thin film units to form an isolation layer. Each quantum dot thin film unit corresponds to a pixel position. By embedding the functional layer within the gaps between adjacent quantum dot thin film units, the quantum dot photodetector array effectively suppresses the movement of photogenerated carriers between adjacent pixels during device operation, thereby improving the detection performance by efficiently suppressing crosstalk. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is an overall structural diagram of the quantum dot photodetector array provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall structure of a quantum dot photodetector array, used as a comparative example of existing technology. Figure 3 The experimental simulation comparison test diagrams are for individual devices corresponding to the comparative scale. Figure 4 Crosstalk comparison diagram for the embodiments and comparative examples; Figure 5 A comparison diagram of the electric fields of the embodiments and comparative examples; Figure 6 A flowchart illustrating the preparation method provided in an embodiment of the present invention.

[0009] Reference numerals: 1. Insulating substrate; 2. Bottom electrode layer; 3. Nickel oxide thin film; 4. Quantum dot thin film; 5. Functional layer; 6. Top electrode layer. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0012] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0013] This invention also provides a quantum dot photodetector array with crosstalk suppression function, such as... Figure 1 As shown, the quantum dot photodetector array includes an insulating substrate 1, a bottom electrode layer 2, a nickel oxide thin film 3, a quantum dot thin film 4, a functional layer 5, and a top electrode layer 6 stacked together. The bottom electrode layer 2 includes multiple metal blocks arranged in an array. There are gaps between adjacent metal blocks, and the insulating substrate 1 is embedded in the gaps between the metal blocks. Each metal block corresponds to a pixel position. The functional layer is made of semiconductor material. The quantum dot thin film 4 includes multiple quantum dot thin film units arranged in an array. There are gaps between adjacent quantum dot thin film units, and the semiconductor material embedded in the gaps between the quantum dot thin film units forms an isolation layer. Each quantum dot thin film unit corresponds to a pixel position.

[0014] In this embodiment, multiple metal blocks are arranged in a matrix to form the bottom electrode layer 2, with gaps between adjacent metal blocks. The insulating substrate 1 is embedded in the gaps between the metal blocks, meaning the gaps are filled with the same insulating material as the insulating substrate 1. Similarly, the quantum dot film 4 includes multiple quantum dot film units arranged in a matrix, with gaps between adjacent quantum dot film units. A functional layer 5 is disposed on the upper layer of the quantum dot film 4, and the semiconductor material corresponding to the functional layer 5 is embedded in the gaps between the quantum dot film units to form an isolation layer, meaning the gaps are filled with the same semiconductor material as the functional layer 5. Each pixel position corresponds to a quantum dot film unit, a metal block, and a functional layer region, a nickel oxide film region, and a top electrode layer region corresponding to the pixel position. The pixel position is as follows: Figure 1 The dashed box indicates the location, and the arrow represents the illumination of surrounding pixels during the test. Existing technologies such as... Figure 2 As shown, the main improvement of this application is that the functional layer 5 is embedded in the gap between the quantum dot thin film units, thereby using semiconductor material as a membrane between the quantum dot thin film units of adjacent pixels. This structure effectively suppresses the movement of photogenerated carriers between adjacent pixels during device operation, and improves the detection effect of the device by efficiently suppressing crosstalk.

[0015] In a more specific embodiment, the semiconductor material is zinc oxide. The spacing between adjacent quantum dot film units is no greater than 1 micrometer. Specifically, the thickness of the functional layer 5 located on top of the quantum dot film 4 is no greater than the thickness of the quantum dot film 4. Further, the thickness of the quantum dot film 4 is 60-100 nanometers.

[0016] In a more specific embodiment, zinc oxide can be used as the semiconductor material to further improve the isolation between quantum dot film units of adjacent pixels. To achieve good application results, the gap between adjacent quantum dot film units can be set to no more than 1 micrometer, and in a preferred embodiment, the gap can be set to 0.2~0.8 micrometers. Further, the thickness of the functional layer 5 on top of the quantum dot film 4 is set to no more than the thickness of the quantum dot film 4. In a preferred embodiment, the thickness of the functional layer 5 on top of the quantum dot film 4 can be set to 45~75 nanometers, and in an optimal embodiment, the thickness of the functional layer 5 on top of the quantum dot film 4 can be set to 60 nanometers. If the thickness of the quantum dot film 4 is set to 80 nanometers, then the total thickness of zinc oxide is 80 nanometers filling the quantum dot film 4 and 60 nanometers serving as the isolation layer (functional layer 5 on top of the quantum dot film 4), that is, the total thickness is 140 nanometers. More specifically, the thickness of the quantum dot film 4 can be set to 60~100 nanometers, in a preferred embodiment, its thickness can be set to 70~85 nanometers, and in an optimal embodiment, its thickness is set to 80 nanometers.

[0017] In a more specific embodiment, the insulating substrate 1 is a silicon wafer substrate with an attached silicon dioxide layer, and the bottom electrode layer 2 is disposed on the silicon dioxide layer, the thickness of which is 150-500 nanometers. The metal block in the bottom electrode layer 2 is gold; the thickness of the bottom electrode layer 2 is 50-100 nanometers.

[0018] like Figure 1 As shown, a silicon wafer substrate with an attached silicon dioxide layer can be used as an insulating substrate 1, and the bottom electrode layer 2 is disposed on the silicon dioxide layer, which has good insulation properties. The thickness of the silicon dioxide layer can be set to 150~500 nanometers, preferably 250~350 nanometers, and in the most preferred embodiment, 300 nanometers. To ensure the structural strength of the device, the thickness of the insulating substrate 1 needs to be greater than 50 micrometers, preferably 200~1000 micrometers. The metal block in the bottom electrode layer 2 is gold, and the thickness of the bottom electrode layer 2 is set to 50~100 nanometers, preferably 60~85 nanometers, and in the most preferred embodiment, 70 nanometers.

[0019] In a more specific embodiment, the nickel oxide thin film 3 has a thickness of 6-25 nanometers. Specifically, the top electrode layer 6 is made of ITO (indium tin oxide) and has a thickness of 40-80 nanometers.

[0020] Furthermore, the thickness of the nickel oxide thin film 3 can be set to 6-25 nanometers, in a preferred embodiment it can be set to 8-15 nanometers, and in the most preferred embodiment it can be set to 10 nanometers. The top electrode layer 6 is made of indium tin oxide, and the thickness of the top electrode layer 6 can be set to 40-80 nanometers, in a preferred embodiment it can be set to 50-65 nanometers, and in the most preferred embodiment it can be set to 60 nanometers.

[0021] This application discloses a preparation method in specific embodiments, wherein the preparation method is used to prepare a quantum dot photodetector array with crosstalk suppression function as described in the above embodiments; please refer to Figure 6 The preparation method includes steps S1 to S6.

[0022] S1. Prepare the bottom electrode pattern by photolithography, and transfer the bottom electrode pattern to the silicon dioxide layer of the insulating substrate by etching; place the insulating substrate in a magnetron sputtering instrument and sputter at a sputtering power of 50~100W for 1.5~4 minutes to obtain the patterned bottom electrode layer; the insulating substrate forms a silicon dioxide layer by thermal oxidation.

[0023] Specifically, the surface of the silicon wafer substrate is thermally oxidized to form a silicon dioxide layer. The silicon wafer substrate with the attached silicon dioxide layer is then used as an insulating substrate. After the bottom electrode pattern is transferred to the silicon dioxide layer of the insulating substrate by etching, the magnetron sputtering power is controlled to be 50~100W and the sputtering time is 1.5~4 minutes. In a preferred embodiment, a sputtering power of 70W is used for 2 minutes and 30 seconds.

[0024] S2. Place the insulating substrate with the bottom electrode layer in a nitrogen glove box and spin-coat a nickel oxide film; the spin-coating speed of the nickel oxide film is 3000~6000 rpm, the spin-coating time is 25~60 seconds, and two layers are spin-coated. After spin-coating the first layer, anneal in air at 80~120℃ for 8~15 minutes, and after spin-coating the first layer, anneal in air at 280~340℃ for 0.8~1.5 hours.

[0025] Furthermore, a nickel oxide film is obtained by spin-coating twice on an insulating substrate. Each spin-coating speed is controlled at 3000-6000 rpm, and the spin-coating time is 25-60 seconds. In a preferred embodiment, the spin-coating speed is 4500 rpm and the spin-coating time is 40 seconds. After spin-coating the first layer, the film is annealed in air at 80-120°C for 8-15 minutes. In a preferred embodiment, it is annealed in air at 100°C for 10 minutes. After spin-coating the second layer, the film is annealed in air at 280-340°C for 0.8-1.5 hours. In a preferred embodiment, it is annealed in air at 300°C for 1 hour.

[0026] S3. Place the insulating substrate with the spin-coated nickel oxide film in a nitrogen glove box and spin-coat the quantum dot film. The spin-coating speed of the quantum dot film is 1600~3000 rpm and the spin-coating time is 15~30 seconds. Then, place the silicon wafer with the spin-coated quantum dot film into a solution containing zinc iodide-mercaptopropionic acid mixed ligands for ligand exchange. Repeat the spin-coating and ligand exchange of the quantum dot film three times.

[0027] Further spin-coating of quantum dot films is performed, with the spin-coating speed controlled at 1600-3000 rpm and the spin-coating time at 15-30 seconds. In a preferred embodiment, the spin-coating speed is 2000 rpm and the spin-coating time is 20 seconds. After spin-coating, zinc iodide (ZnI2)-mercaptopropionic acid (MPA) mixed ligand exchange is carried out. The core of this process is to replace the long-chain organic ligands of the quantum dot film with short-chain ligands through ligand exchange, thereby modifying the surface of the quantum dot film, reducing the defect state density of the quantum dot film, and improving the carrier mobility. The spin-coating and ligand exchange are repeated three times.

[0028] S4. The quantum dot film is patterned using a high-hardness custom mold by nanoimprinting and then annealed at 60~100℃ for 8~15 minutes.

[0029] The quantum dot film is patterned by nanoimprinting using a high-hardness custom mold, and then annealed at 60~100℃ for 8~15 minutes. In a preferred embodiment, it can be annealed at 80℃ for 10 minutes to obtain quantum dot film units arranged in an array.

[0030] S5. Spin-coating semiconductor material in an air environment to form an electron transport layer and an isolation layer, wherein the spin-coating speed of the semiconductor material is 1600~3000 rpm and the spin-coating time is 15~30 seconds.

[0031] Further spin coating of an electron transport layer and an isolation layer, both made of semiconductor materials, is performed. The spin-coated electron transport layer constitutes the functional layer of the aforementioned detector array. The spin coating speed of the semiconductor material is 1600~3000 rpm and the spin coating time is 15~30 seconds. In a preferred embodiment, the spin coating speed is controlled at 2500 rpm and the spin coating time is 20 seconds. This step does not require annealing.

[0032] S6. Sputter the top electrode layer by magnetron sputtering, wherein the sputtering power of the top electrode layer is 35~70W and the sputtering time is 24~40 minutes.

[0033] The top electrode layer is further formed by magnetron sputtering with a sputtering power of 35-70W and a sputtering time of 24-40 minutes; in a preferred embodiment, a sputtering power of 50W can be used for sputtering for 30 minutes.

[0034] Based on the processing technology excluding step S4, a quantum dot photodetector array was fabricated consisting of a 300 nm silicon dioxide layer on a silicon substrate, a 70 nm bottom electrode layer, a 10 nm nickel oxide film, an 80 nm quantum dot film, a 60 nm functional layer, and a 60 nm top electrode layer. As a comparative example, this quantum dot photodetector array is an unpatterned PIN-type photodetector array (device structure as shown in...). Figure 2 As shown, the quantum dot film does not contain quantum dot film units arranged in a matrix. The area of ​​a single pixel is 15 μm × 15 μm, and the optical power density is 0.5 mW / cm². 2 The incident wavelength was 1370 nm. The accuracy of the simulation model was verified by fitting the experimental results of the actual device with the simulated dark current density experimental results. The test results are as follows: Figure 3 As shown. Among them, Figure 3Figure (a) shows the experimental results of dark current density of the real device and the simulated device with a single pixel area of ​​15 μm × 15 μm. Figure 3 Figure (b) shows the experimental results of photocurrent density of the real device and the simulated device of the same size.

[0035] Due to the stringent requirements of the manufacturing process and equipment, quantum dot thin-film photodetector arrays with pixel pitches smaller than 1µm were simulated using simulation experiments to model their electrical performance with pixel pitches ranging from 1µm to 0.1µm. The dark current of the middle pixel was extracted during both dark and illuminated processes involving surrounding pixels. The degree of crosstalk was measured by comparing the dark current fluctuations of the middle pixel during the dark and illuminated processes. The crosstalk fluctuation was calculated using the following formula: Crosstalk degree = [(I2-I1) / I1] × 100%; I2 represents the dark current value of the middle pixel when the surrounding pixels are illuminated, and I1 represents the dark current value of the middle pixel when the surrounding pixels are in darkness. Since the experimental test results of the actual device highly match the simulated experimental results of the light-dark current density, the above... Figure 3 The comparative test results are used to demonstrate the reliability of the subsequent simulation test results.

[0036] Based on the above processing technology, a quantum dot photodetector array with a 300 nm silicon dioxide layer, a 70 nm bottom electrode layer, a 10 nm nickel oxide film, an 80 nm quantum dot film, a 60 nm functional layer, and a 60 nm top electrode layer is simulated as an example. In the example, the quantum dot film includes quantum dot film units arranged in a matrix, and the semiconductor material corresponding to the functional layer is embedded in the gap between adjacent quantum dot film units in the quantum dot film.

[0037] The crosstalk levels between the comparative device and the embodiment device when the pixel pitch is less than 1µm are as follows: Figure 4 As shown, it is clear that when the pixel pitch is less than 1µm, crosstalk increases significantly as the pixel pitch decreases; however, in the embodiment, the quantum dot thin film photodetector array can significantly suppress this crosstalk because it fills the gap with semiconductor material.

[0038] Further testing was conducted on the electric field strength of the quantum dot film (lead sulfide quantum dot film) of the embodiment device at a pixel pitch of 1µm. The test results are as follows: Figure 5 As shown; by Figure 5 It can be observed that after filling the gaps in the quantum dot film with a semiconductor material, the electric field intensity in the pixel spacing is significantly reduced. Since photogenerated carriers will drift under the action of the electric field, the electric field intensity is positively correlated with the drift current density. The weakening of the electric field can effectively suppress the drift current, thereby reducing electrical crosstalk between pixels. Figure 5 Figure (b) is Figure 5A magnified view of region A in Figure (a); the position is the coordinate value corresponding to the cross-section of the device and the horizontal axis.

[0039] This invention provides a quantum dot photodetector array with crosstalk suppression function and its fabrication method. The quantum dot photodetector array includes a stacked insulating substrate, a bottom electrode layer, a nickel oxide thin film, a quantum dot thin film, a functional layer, and a top electrode layer. The bottom electrode layer includes multiple metal blocks arranged in an array. Gaps exist between adjacent metal blocks, and the insulating substrate is embedded within these gaps. Each metal block corresponds to a pixel position. Multiple quantum dot thin film units are arranged in an array, with gaps between adjacent units. The semiconductor material corresponding to the functional layer is embedded within the gaps between the quantum dot thin film units to form an isolation layer. Each quantum dot thin film unit corresponds to a pixel position. By embedding the functional layer within the gaps between adjacent quantum dot thin film units, the quantum dot photodetector array effectively suppresses the movement of photogenerated carriers between adjacent pixels during device operation, thereby improving the detection performance by efficiently suppressing crosstalk.

[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A quantum dot photodetector array with crosstalk suppression function, characterized in that, The quantum dot photodetector array includes a stacked insulating substrate, a bottom electrode layer, a nickel oxide thin film, a quantum dot thin film, a functional layer, and a top electrode layer; The bottom electrode layer includes multiple metal blocks arranged in an array; there are gaps between adjacent metal blocks, and the insulating substrate is embedded in the gaps between the metal blocks; each metal block corresponds to a pixel position; the functional layer is made of semiconductor material. The quantum dot film includes multiple quantum dot film units arranged in an array, with gaps between adjacent quantum dot film units. Semiconductor material embedded in the gaps between the quantum dot film units forms an isolation layer, and each quantum dot film unit corresponds to a pixel position.

2. The quantum dot photodetector array with crosstalk suppression function according to claim 1, characterized in that, The semiconductor material is zinc oxide.

3. The quantum dot photodetector array with crosstalk suppression function according to claim 2, characterized in that, The gap between adjacent quantum dot thin film units is no greater than 1 micrometer.

4. The quantum dot photodetector array with crosstalk suppression function according to claim 3, characterized in that, The thickness of the functional layer located on top of the quantum dot film is no greater than the thickness of the quantum dot film.

5. The quantum dot photodetector array with crosstalk suppression function according to claim 4, characterized in that, The thickness of the quantum dot film is 60-100 nanometers.

6. The quantum dot photodetector array with crosstalk suppression function according to any one of claims 1-5, characterized in that, The insulating substrate is a silicon wafer substrate with an attached silicon dioxide layer, and the bottom electrode layer is disposed on the silicon dioxide layer; the thickness of the silicon dioxide layer is 150~500 nanometers.

7. The quantum dot photodetector array with crosstalk suppression function according to claim 6, characterized in that, The metal block in the bottom electrode layer is gold; the thickness of the bottom electrode layer is 50~100 nanometers.

8. The quantum dot photodetector array with crosstalk suppression function according to claim 7, characterized in that, The thickness of the nickel oxide film is 6-25 nanometers.

9. The quantum dot photodetector array with crosstalk suppression function according to claim 8, characterized in that, The top electrode layer is made of indium tin oxide and has a thickness of 40-80 nanometers.

10. A preparation method, characterized in that, The preparation method is used to prepare a quantum dot photodetector array with crosstalk suppression function as described in any one of claims 1-9, and the preparation method includes: The bottom electrode pattern is prepared by photolithography, and then transferred to the silicon dioxide layer of the insulating substrate by etching. The insulating substrate is placed in a magnetron sputtering instrument and sputtered at a sputtering power of 50~100W for 1.5~4 minutes to obtain a patterned bottom electrode layer. The insulating substrate is then thermally oxidized to form a silicon dioxide layer. An insulating substrate with a bottom electrode layer is placed in a nitrogen glove box and a nickel oxide film is spin-coated. The spin-coating speed of the nickel oxide film is 3000~6000 rpm and the spin-coating time is 25~60 seconds. Two layers are spin-coated. After the first layer is spin-coated, the substrate is annealed in air at 80~120℃ for 8~15 minutes. After the first layer is spin-coated, the substrate is annealed in air at 280~340℃ for 0.8~1.5 hours. An insulating substrate with a spin-coated nickel oxide film is placed in a nitrogen glove box for spin-coating a quantum dot film. The spin-coating speed of the quantum dot film is 1600~3000 rpm and the spin-coating time is 15~30 seconds. The silicon wafer after spin-coating to form a quantum dot film is placed in a solution containing a zinc iodide-mercaptopropionic acid mixed ligand for ligand exchange. The spin-coating and ligand exchange of the quantum dot film are repeated 3 times. The quantum dot film was patterned using a high-hardness custom mold via nanoimprinting and then annealed at 60-100°C for 8-15 minutes. Semiconductor materials are spin-coated in an air environment to form an electron transport layer and an isolation layer, wherein the spin-coating speed of the semiconductor material is 1600~3000 rpm and the spin-coating time is 15~30 seconds; The top electrode layer is sputtered by magnetron sputtering, with a sputtering power of 35-70W and a sputtering time of 24-40 minutes.

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